Method and apparatus for masking keystroke sounds from computer keyboards

ABSTRACT

Disclosed herein is a method of masking audible sounds emanating from a keyboard in response to a stroking of keys on the keyboard, the method comprising, selecting components from a plurality of components with various masses, building the keyboard with the selected components, moving a movable mass within the keyboard, and energizing a driving transducer within the keyboard. Further disclosed herein is a keyboard for a computer, comprising a plurality of keys, a cover with the keys protruding therethrough, a base supporting the cover and the keys, and at least one selectable mass wherein the mass is selected from a plurality of masses, a movable mass supported by the base and movable relative to the base, and a driving transducer supported by the base.

TRADEMARKS

IBM® is a registered trademark of International Business MachinesCorporation, Armonk, N.Y., U.S.A. Other names used herein may beregistered trademarks, trademarks or product names of InternationalBusiness Machines Corporation or other companies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to computer keyboards and particularly to thesounds emitted from a keyboard as keys of the keyboard are stroked.

2. Description of Background

Technology now exists that makes it possible to determine which keys arestroked on a computer keyboard by recording the sound that emanates fromthe keyboard as the keys are stroked and processing the recorded soundin a personal computer (PC).

Using input from an unsophisticated PC microphone and processing theinput using standard machine learning and speech recognition techniquesit is possible to recreate typed input with up to 96% accuracy. Using atwo-phase process of training followed by recognition, researchers wereable to successfully recreate both English and random (password) inputfrom multiple keyboards, across various (quiet and noisy) environments.While techniques such as the one described are still relatively new, onecan envision several nefarious uses for the technology. For example, aperson using a parabolic microphone could sit in a public setting, suchas a coffee shop with Internet access, and eavesdrop on other patrons;recording sensitive information keyed into their computers, such aspasswords and credit card numbers.

Accordingly, there is a need in the art for methods and apparatuses thatinhibit the detection of keystrokes by the sounds emanating duringstroking of the keys.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome and additional advantagesare provided through the provision of a method of masking audible soundsemanating from a keyboard in response to a stroking of keys on thekeyboard, the method comprising, selecting components from a pluralityof components with various masses, building the keyboard with theselected components, moving a movable mass within the keyboard, andenergizing a driving transducer within the keyboard.

Further shortcomings of the prior art are overcome and additionaladvantages are provided through the provision of a keyboard for acomputer, comprising a plurality of keys, a cover with the keysprotruding therethrough, a base supporting the cover and the keys, andat least one selectable mass wherein the mass is selected from aplurality of masses, a movable mass supported by the base and movablerelative to the base, and a driving transducer supported by the base.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with advantagesand features, refer to the description and to the drawings.

TECHNICAL EFFECTS

The technical effect of the disclosed embodiments is improved securitywhen using a computer keyboard in a public setting. Specifically, thetechnical effect is to inhibit the deciphering of which key of akeyboard is stroked based on the sound that emanates from the keyboardas the key is stroked. Computer algorithms for noise cancellation areknown in the audiophile industry and are applied to listening to music,for example, in an environment with a noisy background such as on anairplane. Application of similar techniques to attenuate the sounds thatare projected from a computer keyboard during the stroking of keys onthe keyboard is disclosed.

As a result of the summarized invention, a solution has been devisedthat permits a computer user to key in private information, such aspasswords and credit card numbers, in a public setting while preventingkeystroke detection based on the sounds emanating from the keys as theyare depressed.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 illustrates one example of a plan view of a keyboard disclosedherein;

FIG. 2 illustrates one example of an edge view of the keyboard of FIG.1;

FIG. 3 illustrates one example of a cross sectional view of anembodiment of the keyboard in FIG. 2 taken at section line 3-3;

FIG. 4 illustrates one example of a cross sectional view of anembodiment of the keyboard of FIG. 1 taken at section line 4-4;

FIG. 5 illustrates one example of a cross sectional view of anembodiment of the keyboard in FIG. 2 taken at section line 5-5;

FIG. 6 illustrates one example of a cross sectional view of anembodiment of the keyboard of FIG. 1 taken at section line 6-6;

FIG. 7 illustrates one example of a plan view of a key of the keyboardof FIG. 1;

FIG. 8 illustrates one example of a cross sectional view of the key ofFIG. 7 taken at section line 8-8;

FIG. 9 illustrates one example of a cross section view of an embodimentof the keyboard in FIG. 2 taken at section line 9-9; and

FIG. 10 illustrates one example of a cross sectional view of anembodiment of the keyboard of FIG. 1 taken at section line 10-10.

The detailed description explains the preferred embodiments of theinvention, together with advantages and features, by way of example withreference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings in greater detail, it will be seen that inFIGS. 1 and 2 there is a computer keyboard shown generally at 10 inaccord with an embodiment of the invention. The keyboard 10 among otherthings includes; keys 14 that protrude through a cover 18 that isattached to and supported by a base 22. Each of the keys 14 is springloaded in a direction away from the base 22 and can move in a directiontowards the base 22 in response to being depressed by an operator. Uponrelease, by the operator, the spring loading returns the keys 14 totheir original position.

Each key 14 has a unique X-Y coordinate position relative to the cover18 and the base 22. Additionally, each key 14 also has a unique positionrelative to the other keys 14 on the keyboard 10. This positionaluniqueness results in a unique audible sound being emitted for every key14 when it is stroked. This is partially due to the flat shape anduniform thickness of the base 22, which forms a sounding board. Sound(pressure waves) generated from the depression of a key 14 impacts aspecific location on the base 22 in accord with its coordinate positionrelative to the base 22. This position on the base being a uniqueposition creates a unique response from the base 22. Disruption of theacoustic sounding board of the base 22 is easily achieved by theintroduction of a mass to the keyboard 10.

Referring to FIGS. 3 and 4, cross sectional views of the keyboard 10 ofFIGS. 2 and 1, taken at arrows 3-3 and 4-4 respectively, are shown. Amoveable mass 26 is able to move along slide 30 in the directions ofplus X and minus X in a cavity 34 of the keyboard 10 between the keys 14and the base 22. The cavity 34, by being located between the keys 14 andthe base 22 may hide the mass 26 and its location from the operator aswell as any other observer. The mass 26 may be formed of iron or othermagnetic metal, for example, and may therefore be attracted toelectromagnets 38 located near the four corners 42 of the keyboard 10.Energization of the electromagnets 38 may cause movement of the mass 26along the slide 30. Movement of the mass 26 may result in a change tothe acoustics of the keyboard 10 enough to alter the sound emitted bythe keyboard 10 when any specific key 14 is stroked to prevent detectionby analysis of the sound emitted.

Energization of the electromagnets 38 may be controlled by a variety ofinputs. For example, a random number generator could be used in responseto each keystroke resulting in a random direction and random distance ofmovement of the mass 26. Alternately, a predefined movement of the mass26 could occur regardless of which key is stroked. The electrical powerthat energizes the electromagnets 38 could be supplied from whateversource the PC is receiving power, for example, a battery or from an ACpower source.

Alternatively, the mass 26 could be moved through a mechanical linkageto the keys 14 rather than using the electromagnets 38. Such a systemcould use linkages (not shown) to move the mass 26 in a plus X or aminus X direction, for example, from its current location in response tothe stroking of the keys 14. Additionally, the mass 26 could be moved ina plus Y and minus Y direction with any applicable method while notdeviating from embodiments of the present invention.

Referring now to FIGS. 5 and 6, cross sectional views of the keyboard 10of FIGS. 2 and 1, taken at arrows 5-5 and 6-6 respectively, are shown.Similar to the embodiment of FIGS. 3 and 4, FIGS. 5 and 6 use theredistribution of mass within cavity 34, formed between the keys 14 andthe base 22, to disrupt the sound that emanates from the keyboard 10when keys 14 are stroked. In embodiments disclosed in FIGS. 5 and 6, themovement of mass 26 is carried out by locally deforming a bag 50 that ispartially filled with a fluid 54, herein depicted as a liquid. Thedeformation occurs when protrusions 58, from the keys 14, push on thesurface of the bag 50 thereby forming a local depression in the bag 50.Gas pockets 62, within the bag 50, redistribute themselves as thebuoyancy force acting on the gas pockets 62 push the gas pockets 62 tohigher elevations. Consequently, locations of the gas pockets 62, withinthe bag 50, changes with every keystroke causing a randomization of thelocation of the mass 26, which is the fluid 54, to occur. Additionally,the attitude and movement of the keyboard 10 itself will cause the fluid54 to move within the bag 50, thereby adding to the randomness of themass 26 distribution.

Alternate embodiments may employ a cavity 34 that contains the fluid 54in such a way that it is sealed without the use of a bag 50. Such anembodiment may decrease the force required to depress the key 14 duringa keystroke since no bag 50 would be undergoing deformation.

Referring to FIGS. 7 and 8, the keys 14 include a protrusion 58 thatextends from the underside of the keys 14 and engages the bag 50, forexample, in the cavity 34, as described above. Many of the keys 14 havethe same shape as one another and are made from the same plasticmaterial and are therefore injection molded in the same mold. Thecharacter may be subsequently printed thereon. An embodiment of theinvention shown in FIGS. 7 and 8 includes provisions for moldingoptional ribs 66 on the underside of the keys 14. Molds can be insertedto facilitate easy changeover between various rib configurations. Theoptional ribs 66 can be of various lengths and widths to afford the keys14 a wide variety of different masses. A short rib 65, a longer rib 67and even longer rib 68 are shown in phantom as possible variations. Thekeys 14 with various rib lengths and associated masses may be mixedtogether prior to character printing to increase the randomness of themass that each character key 14 will have. Each different key mass mayalter the sound that is emitted by the keyboard 10 when each key 14 isdepressed, thereby creating a very large number of permutations ofsounds that may emanate from any specific keyboard 10. The larger thenumber of total sounds that may emanate from a keyboard 10, the more thecharacteristics of the sounds from different keystrokes will overlapcreating greater difficulty in determining which key 14 caused eachsound. Such overlapping of keystroke sounds may render which key 14 wasthe source of which sound undeterminable. The foregoing embodimentdiscloses keyboards 10 made from selectable masses, disclosed herein askeys 14, although, it should be noted that other components within thekeyboard could be selectable as well with varying masses to create avariety of different possible keyboard mass combinations.

The foregoing embodiment, which relies on the different masses of keys14 to thwart the determination of keystrokes, is a passive approach,while an embodiment of FIGS. 9 and 10, relies on an active approach.Referring now to FIGS. 9 and 10, cross sectional views of the keyboard10 of FIGS. 2 and 1, taken at arrows 9-9 and 10-10 respectively, areshown. Specifically, the keyboard 10, among other things includes; areceiving transducer 70, such as an accelerometer microphone or otherdevice for converting vibrational or acoustical energy into electricalenergy, located within the cavity 34 of the keyboard 10 that laysbetween the keys 14 and the base 22. The receiving transducer 70 sensesthe vibrations of the keyboard 10 that result from each stroke of a key14. The signal from the receiving transducer 70 is then processed, by aprocessor (not shown) and a response signal is sent to a drivingtransducer 74 such as a piezoelectric transducer, an audio speaker orother device for converting electrical energy into mechanical energy,also located within the cavity 34. The response signal may be 180degrees out of phase with the signal sensed by the receiving transducer70 such that the waves generated by the driving transducer 74 cancelwaves from the stroking of keys 14 thereby attenuating the magnitude ofthe emanating sounds. Stated another way, the driving transducer 74, bygenerating waves that are 180 degrees out of phase with the receivingwaves, will create sound pressure waves that destructively interfereand, in effect, cancel the receiving sound pressure wave.

An alternate embodiment may utilize the input from the receivingtransducer 70 to time the sending of a random noise signal to thedriving transducer 74. Such a system may transmit a random noise, orwhite noise, instead of an out of phase noise to cover the sounds madeby the keystrokes, thereby making detection of a clean keystroke sounddifficult. Still other embodiments may not utilize the receivingtransducer 70 or a speaker to detect the sound emanating from a strokedkey 14 at all, but instead rely on the electrical signal generated bythe keystrokes themselves to determine the timing of when to energizethe driving transducer 74.

Embodiments of the invention may include some of the followingadvantages: attenuation of sound emanating from a keyboard, masking ofsounds emanating from a keyboard, increased variations of soundsemanating from a keyboard, alteration of sounds emanating from akeyboard, continuously randomly modifying sounds emanating from akeyboard and changing, over time, the sound emanating from a keyboard inresponse to a given key being stroked.

The capabilities of the present invention can be implemented insoftware, firmware, hardware or some combination thereof.

As one example, one or more aspects of the present invention can beincluded in an article of manufacture (e.g., one or more computerprogram products) having, for instance, computer usable media. The mediahas embodied therein, for instance, computer readable program code meansfor providing and facilitating the capabilities of the presentinvention. The article of manufacture can be included as a part of acomputer system or sold separately.

Additionally, at least one program storage device readable by a machine,tangibly embodying at least one program of instructions executable bythe machine to perform the capabilities of the present invention can beprovided.

While preferred embodiments to the invention have been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

1. A method of masking audible sounds emanating from a keyboard inresponse to a stroking of keys on the keyboard, the method comprising:selecting components from a plurality of components with various masses;building the keyboard with the selected components; moving a movablemass within the keyboard; and energizing a driving transducer within thekeyboard.
 2. The method of claim 1, wherein the movement of the movablemass is by magnetic force.
 3. The method of claim 1, wherein themovement of the movable mass is varied based on which keys are stroked.4. The method of claim 1, wherein the movement of the movable mass israndom.
 5. The method of claim 1, wherein the movable mass is a liquid.6. The method of claim 1, wherein the selecting is done at random. 7.The method of claim 1, wherein the components selected are keys.
 8. Themethod of claim 1, wherein the timing of the energization of thetransducer coincides with the stroking of keys.
 9. The method of claim8, wherein the energization of the transducer varies depending upon thesound emanating from the keystrokes.
 10. The method of claim 8, whereinthe energization of the transducer cancels sounds emanating from thekeystrokes.